Their new bill, called the Honest Ads Act, would make political ads on social media subject to the same transparency and disclosure laws as TV and radio ads.

Sen. John McCain (Ariz.), who helped co-write the legislation, is the first Republican to sign on as a co-sponsor.

In a release from Warner and Klobuchar’s offices, the lawmakers blamed a lack of ad disclosure laws on social media as a contributing factor in how Russian actors may have taken advantage of the platforms.

Since Facebook revealed that a Kremlin-linked group purchased $100,000 worth of ads around the time of the 2016 election, Warner and Klobuchar have floated revised Federal Election Commission regulations that would force social media companies like Facebook and Twitter to disclose who is buying political ads on their platforms.

“As much as I dislike Citizens United, at least someone can look at the TV ads being run for or against somebody,” Warner said last month. “Why don’t those rules apply to social media companies?”

According to a draft of a letter that the two circulated in September to other lawmakers seeking support for the bill, digital platforms with over 1 million users would be required “to maintain a public file of all electioneering communications purchased by a person or group who spends more than $10,000 aggregate dollars for online political advertisements.”

Broadcast, cable and satellite providers will also need to take additional steps to keep foreign actors from potentially using their platforms to influence elections.

Warner, the top Democrat on the Senate Intelligence Committee, has been one of the most vocal lawmakers in Congress on the matter of potential Russian election interference. In addition to the forthcoming legislation, the Virginia Democrat has pushed technology companies like Facebook, Twitter and Google to provide both Congress and the public more details on the extent of Russian influence on their platforms.

Representatives from the companies are scheduled to testify over such interference at consecutive House and Senate Intelligence Committee hearings on Nov. 1.